Curr Urol Rep (2016) 17:21 DOI 10.1007/s11934-016-0579-1
UROTHELIAL CANCER (A SAGALOWSKY, SECTION EDITOR)
A Review Comparing Experience and Results with Bipolar Versus Monopolar Resection for Treatment of Bladder Tumors Yasser Osman 1 & Ahmed M. Harraz 1
# Springer Science+Business Media New York 2016
Abstract The standard treatment of non-muscle invasive bladder cancer (NMIBC) is transurethral resection (TUR) commonly using a monopolar electrocautery system. This system requires high energy and voltage to allow an electric current to run from the loop to the patient’s skin. The heat generated leads to desiccation of small cells and difficulty to perform adequate histological analysis for severely cauterized pieces of tissues. On contrary, the electric current in bipolar systems does not traverse the patient and hence lower energy and voltage are used and minimal tissue damage is anticipated. In addition, the use of saline as an irrigant fluid eliminates the potential TUR syndrome from excess hypotonic fluid reabsorption. Furthermore, the lower energy dissipates as heat in tissues contributing to adequate hemostasis. This review presents the most recent studies and evidence on the differences between monopolar and bipolar systems for TUR of NMIBC as regards the perioperative and long-term outcomes. Keywords Non-muscle invasive bladder cancer . Bipolar plasma kinetic energy . Transurethral resection
Introduction Urothelial (UC) carcinoma of the bladder is the most common malignancy of the urinary tract and it ranks the 7th and 17th This article is part of the Topical Collection on Urothelial Cancer * Yasser Osman [email protected]
1
Urology and Nephrology Center, Mansoura University, 70th Gomhoria St., 35516 Mansoura, Egypt
most common cancer worldwide among males and females, respectively [1]. Each year, approximately 110,500 men and 70,000 women are newly diagnosed with approximately 75 % of patients present with non-muscle invasive bladder cancer (NMIBC) [1, 2]. The most significant risk factor is smoking accounting for more than half of the patients while genetic and epigenetic alterations related to carcinogenesis in the bladder have been linked to environmental and occupational factors in non-smokers [3]. The mortality from UC reaches up to 38,200 patients in the European Union and 17,000 in US patients [1]. The standard treatment for NMIBC is transurethral resection (TUR) aiming at confirming the diagnosis and removal of all visible lesions which is crucial for prognosis [4]. Monopolar systems used for TUR of NMIBC require the use of high energy and voltage to allow the current transmission from the loop to the skin. The heat generated from this current not only facilitates the cutting of tissues; unfortunately, it causes desiccation of small cells. In addition, it is difficult to perform adequate histological analysis for severely cauterized pieces of tissues [5]. Bipolar technology has been introduced and is gaining popularity among urologists for treatment of benign prostatic obstruction [6]. In this system, the electric current completes the circuit, without passing through the patient, between the two poles situated on the tip (Btrue^) or between the active (resection loop) and passive pole situated on specifically developed sheath (Bquasi-^). This allows isotonic fluid to be used for irrigation instead of electrolyte-free solutions and, hence, eliminating the occurrence of transurethral syndrome with monopolar systems. In addition, the bipolar systems use the plasma formed at the surface of the electrode to minimize voltage needed for tissue resection. Furthermore, the energy and voltage required is lower as there is a short distance to travel compared to loop-to-skin distance in monopolar system [6]. Another difference between the monopolar and bipolar
21
Curr Urol Rep (2016) 17:21
Page 2 of 6
systems is the coagulation mechanism. In the bipolar system, the voltage is kept low and the energy dissipates as heat in tissues leading to the formation of coagulum and hemostasis. Recently, comparable outcomes between bipolar and monopolar TURP were reported as regards perioperative morbidity and improvement in symptom scores even in subpopulations with large prostates [6–9]. In this context, the use of bipolar technology for TUR of bladder tumor (TURBT) is growing and has become of great interest in many centers [5, 10••, 11–13]. This review presents the current status of bipolar TURBT compared with traditional monopolar TURBT.
Evolution of Bipolar TURBT Traditionally, TURBT was performed with monopolar electrocautery as the base of diagnosis and initial therapy since its introduction in 1910 [14]. Three decades ago, the concept of controlled bipolar high-frequency coagulation for transurethral destruction of urinary bladder tumors was experimentally introduced [15, 16]. Few years later, in vivo trials showed that bipolar probes could electrodesiccate at a lower power and with less tissue damage in a porcine bladder model [17]. Nevertheless, the clinical application was delayed in order to ensure that bipolar probes could provide meticulous, safe, and complete tumor resection. Moreover, excessive tissue destruction should be avoided to allow adequate pathological assessment. A decade ago, two small case series were reported from USA and Germany and showed bipolar tumor resection can be performed safely with excellent control of the extent of cutting and the lack of nerve stimulation. Bladder tissue obtained from bipolar TURBT is of the same histologic quality as that obtained from conventional monopolar TURBT and provides the urologists with reliable and complete diagnosis [18, 19]. At that time, the technique was generally limited for risky patients as pregnant women and those with implanted pacemakers [20, 21]. Pu et al. reported the first wide clinical experience in year 2008 where 121 patients were treated with bipolar resection of superficial bladder tumors. Adductor contractions were observed in 4.9 % of the patients with bladder wall perforation in 1.7 % while hematuria was encountered in 2.5 %. The procedure was described to be a safe and effective modality in treating superficial bladder tumors [13]. In an Italian report, Puppo et al. reported 1000 cases with transurethral resection in saline utilizing the bipolar devices including 480 cases of bladder neoplasm resection. Obturator nerve stimulation was reported in 2 % of cases with no bladder wall perforation. Clot retention was experienced in 2 % of patients with less than 1 % requiring blood transfusion. The technique was described to guarantee maximum safety for the patients [22].
Evaluation of Bipolar TURBT Yet, comparative studies were mandatory to critically judge the outcome compared with the standard monopolar resection. Nine comparative studies were reviewed [5, 10••, 18, 23, 24•, 25, 26••, 27, 28] among three were controlled prospective randomized trials [10••, 24•, 26••]. Anesthesia Time The loop size utilized with bipolar resection is generally smaller than the classic monopolar loop typically used [28]. On the other hand, utilizing bipolar resection was expected to reduce resection time due to reduced adhesions of residual fragments to the loop of a resectoscope which are easily removed by acting on the cutting function with the loop in the bladder lumen. In contrast, the monopolar device requires a manual and mechanical removal of the residual chips through extraction of the instrument from its sheath which prolongs the procedure [29]. Generally, non-randomized [5, 25, 27, 28] as well as randomized [10••, 24•, 26••] studies confirmed that resection time was equal regardless of the type of energy utilized. Bleeding Based on the prostatic experience, bipolar resection was believed to induce better hemostasis as the deep coagulation and the cut and seal property of the bipolar current contribute to augment the ability to control bleeding points [30–32]. Apart from a single non-randomized comparative study that showed a significant drop of hemoglobin level with monopolar TURBT compared with bipolar resection that was not reflected on the transfusion rate [28], bleeding events, transfusion rates, need for re-coagulation, and decrease in packed cell volume were persistently reported to be comparable between both techniques in both non-randomized as well as randomized reports [5, 10••, 24•, 25, 26••, 27, 28]. Transurethral Resection Syndrome Transurethral resection syndrome (TUR) syndrome after bladder tumor resection was first described by Hahn in 1995 [33]. The use of normal saline for bladder irrigation during bipolar resection practically precludes the possibility of TUR syndrome. Generally, TUR syndrome after monopolar TURBT is rarely reported with an incidence around 2 % [34]. The rarity of this complication led to absence of a significant difference between both techniques in clinical TUR syndrome or even subclinical change in sodium level between monopolar and bipolar tumor resection [10••, 26••, 27].
Curr Urol Rep (2016) 17:21
Urethral Stricture Ho reported higher incidence of urethral strictures in patients treated with bipolar resection of the prostate compared with monopolar resection although it does not reach a statistical significance [35]. It was suggested that increased electrical density on the outer surface of the sheath of the resectoscope with minute damage on its surface can cause dispersions of flow on the urethral mucosa. Moreover, the use of conductive lubricants might increase the insult [36]. In early reports of bipolar TURBT, high incidence of urethral stricture (4 %) was reported [13]. Later, Puppo et al. reported lower incidence and advised a new loop for each resection to decrease such sequel [22]. Both non-randomized and randomized trials denied a significant difference between either technique in the development of urethral stricture [10••, 27]. Obturator Jerk An incidence of obturator jerk during transurethral resection of bladder tumors is variable according to the type of anesthesia employed and the site of the tumor. Typically, general anesthesia with neuromuscular paralysis is advised to decrease the likelihood of obturator reflex during TURBT for laterally situated tumors [37]. Lee et al. described a technique of ultrasound-guided obturator nerve block in which 1 % lidocaine with epinephrine is injected in the fascial space between adductor longus and adductor brevis muscles with 96 % success rate under spinal anesthesia [38]. A technique of transurethral obturator nerve block was also described with similar success rate [39]. In monopolar resection, the distance between the resecting loop and the return electrode (skin pad) is long resulting in the generation of a high voltage to push the current to the return electrode, explaining the high incidence of obturator nerve stimulation especially with the close proximity between the lateral wall of the bladder and the obturator nerve. A possible mechanism for obturator reflex with bipolar resection includes current transmission secondary to the initial high voltage needed to generate the plasma vapor pocket. Current mushrooming occurs around the electrode and is transmitted a few millimeters deep in the body. The close proximity of the bladder wall and the nerve means that even that limited transmission is sufficient to induce nerve stimulation [11, 22]. The classic incidence of obturator jerk with monopolar resection is 11 % [40, 41] while it ranges in bipolar series from 2 to 4.9 % [13, 22]. Reporting the incidence and the differences between both techniques in inducing obturator reflex is the seat of strong debate and confusion. Some reports described obturator reflex to occur in nearly half the patients [26••] and others reported an incidence around 1 % [10••] regardless of the type of power utilized. One nonrandomized report favored the bipolar TURBT in abolishing
Page 3 of 6 21
the obturator reflex in a statistically significant way compared with monopolar TURBT [27]. A similar study showed equal incidence between both techniques with an equal need of muscle relaxants [5]. The debate extends further into the randomized trials where two studies denied a significant difference between both techniques [10••, 26••] with the third study showing a significant decrease of the incidence of nerve stimulation from 26 % with monopolar resection compared to 4.8 % in the bipolar setting [24•].
Bladder Perforation Although the incidence of bladder injury is rare but it is of concern as it has a high risk of extravesical tumor seeding [8, 42, 43]. Real incidence of bladder perforation might be underestimated possibly because of underreporting, and it ranges from 1.7 to 5 % [13, 44]. Under dedicated postoperative imaging, real incidence of perforation might reach up to 58 % [45]. Similar to obturator reflex debate, the value of bipolar resection in decreasing the incidence of bladder perforation is yet to be confirmed. In a population-based Japanese study that included around 30,000 patients from 788 hospital records, incidence of severe bladder injury was significantly higher in monopolar TURBT based on multivariate analysis [25]. Other non-randomized trials provided opposing conclusions [5, 27]. Mansor et al., in a controlled randomized trial, reported 13.2 % perforation rate with monopolar resection that was significantly higher than the 2.4 % incidence reported with the bipolar resection [24•]. Interestingly, the other two controlled randomized trials failed to sustain that conclusion [10••, 26••]. In another study, Gupta reported a significant rate of obturator jerks and subsequent perforation in their first 10 patients when the power setting of the bipolar machine was adjusted for 160 and 80 W for cutting and coagulation, respectively [11]. They showed that such complications had been eliminated by using a lower power setting of 50 and 40 W [11]. This report should be taken cautiously as the high power setting (or even higher) was adopted in other experiences, and such observation was not reported [5, 13, 22, 27, 28]. To put an end to the controversy regarding the real impact of bipolar TURBT in reducing incidence of obturator nerve stimulation and bladder perforation, we do believe that urologic literature is lacking a critically judged randomized trial. Therefore, a multicenter trial is warranted with standardization of the type of the anesthesia, site of the tumor, skill of the surgeon as well as the power level for both cutting and coagulation mood. Moreover, precise definitions of obturator reflex and bladder perforation are to be provided possibly with EMG recording and routine post-operative imaging.
21
Curr Urol Rep (2016) 17:21
Page 4 of 6
Catheterization, Hospital Stay, and Cost The impact of bipolar resection on catheterization time was controversial on non-randomized trials [5, 28]. Del Rosso in a randomized clinical trial showed significant reduction of the catheterization time with bipolar TURBT into 1.3 days compared with 2.3 days in the monopolar arm [10••]. The policy of hospital stay is variable from institute to another and from a country to another. There is a universal agreement that application of bipolar resection would decrease the hospital stay [10••, 25, 27] possibly because of shorter irrigation [27] and catheterization [10] time. In a population-based study, the overall cost was significantly higher in the monopolar arm compared to bipolar in both univariate and multivariate analyses probably because of shorter hospital stay [25]. Pathological Quality Rationally, the pathological specimen retrieved should not be compromised and must be suitable for elegant pathological assessment. Two non-randomized trials showed that muscularis propria was present in 100 % of cases with bipolar resection compared with 90 to 100 % in monopolar resection [5, 18]. Similarly, Venkatramani et al. confirmed that the deep muscle was retrieved in around 95 % of cases of both groups with no difference based on a controlled randomized trial [26••]. On the other hand, others showed that deep biopsy specimen thickness was significantly thinner with bipolar resection compared with the monopolar resection (2.3 ± 0.9 vs. 3 ± 1.4 mm). Nevertheless, this was sufficient for the pathologist to make appropriate diagnosis in all the cases [28]. In monopolar resection, electrical injury is directed into the tissues and the electrical resistance creates temperature as high as 400 ° C with tissue desiccation and considerable collateral tissue damage. On the other hand, the radiofrequency energy of the bipolar systems converts the conductive medium into a plasma field of highly ionized particles which disrupts the organic bonds between the tissues which allows the thermal effect to occur at a much lower temperature (40 to 70 °C) (37– 39). Thermal damage was categorized into three groups according to quantity of thermal artifacts. Grade 1 was defined as cautery artifact less than one third of the entire specimen. Tissue hips with one third to two thirds cautery artifacts were categorized as grade 2, and tissue chips with over two thirds cautery artifacts were categorized as grade 3 [28]. Several non-controlled studies showed that the incidence of cautery artifact was comparable in the specimens retrieved from both techniques and does not interfere with the diagnostic readability of the specimen [5, 18, 23, 28]. Lagerveld et al. [23] measured the mean depth of the thermal artifact zone was 0.237 mm in the bipolar arm compared with 0.260 mm in the monopolar group. This difference is not significant (P = 0.8). Based on two controlled randomized trials, while the
pathologist was blinded to the technique utilized, the thermal artifacts were significantly higher in the monopolar resection compared with bipolar TURBT [10••, 26••]. Recurrence Rate It was apparent that there was no impact on the recurrence rate whatever type of energy utilized. Median time until bladder recurrence and overall 2-year recurrence rate were equal in both techniques even when stratified into low-, intermediate-, and high-risk groups [10••, 27].
Bipolar Plasma Vaporization This technique was first introduced by a Romanian group in 2011 [12] and starts by multiple biopsies from the exophytic part of the tumor to judge the tumor grade. This is to be followed by tumor plasma vaporization. Upon completion, multiple biopsies of the tumor bed are performed in order to judge the tumor stage. Later, they provided a randomized trial comparing this technique with classic monopolar resection with significantly improved resection time, hemostasis, catheterization time, and hospital stay. Also, they showed a reduced incidence of obturator nerve stimulation and bladder wall perforation significantly. Moreover, residual tumors at second look, primary site recurrence as well as overall recurrence rate at 1 year were significantly higher in the monopolar arm. Notably, these outstanding results were reported when this therapeutic approach is combined with narrow band imaging (NBI) in order to improve the diagnostic ability [46–49]. These data should be interpreted separately from other reports of bladder tumor management utilizing the bipolar energy as the technique includes tumor vaporization rather than resection. Concerns should be raised regarding proper pathological assessment of the tumor bed. A superficial muscle invasion might be easily overlooked during tumor ablation with negative biopsies from deeper muscle layer. This technique was not reproduced with the exception of a small Canadian study [50].
Conclusion The use of bipolar technology in transurethral resection of non-muscle invasive bladder cancer is a safe and effective modality. No solid evidence can be provided that technique would lead to improvement in resection time or hemostasis. Similarly, the current level of evidence did not reduce incidence of urethral stricture, TUR syndrome, or tumor recurrence rate. On the other hand, a better specimen could be provided for pathological assessment with significantly lower thermal artifacts. A well-designed randomized trial is
Curr Urol Rep (2016) 17:21
mandatory to critically judge the impact of bipolar resection upon obturator nerve stimulation and bladder perforation. Compliance with Ethical Standards Conflict of Interest Yasser Osman and Ahmed M Harraz each declare no potential conflicts of interest. Human and Animal Rights and Informed Consent This article does not contain any studies with human or animal subjects performed by any of the authors.
References Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance 1.
2.
3.
4.
5.
6.
7.
8.
9.
10.••
Burger M, Catto JW, Dalbagni G, Grossman HB, Herr H, Karakiewicz P, et al. Epidemiology and risk factors of urothelial bladder cancer. Eur Urol. 2013;63:234–41. Babjuk M, Burger M, Zigeuner R, Shariat SF, van Rhijn BW, Comperat E, et al. EAU guidelines on non-muscle-invasive urothelial carcinoma of the bladder: update 2013. Eur Urol. 2013;64:639–53. Kiriluk KJ, Prasad SM, Patel AR, Steinberg GD, Smith ND. Bladder cancer risk from occupational and environmental exposures. Urol Oncol. 2012;30:199–211. Mariappan P, Finney SM, Head E, Somani BK, Zachou A, Smith G, et al. Good quality white-light transurethral resection of bladder tumours (GQ-WLTURBT) with experienced surgeons performing complete resections and obtaining detrusor muscle reduces early recurrence in new non-muscle-invasive bladder cancer: validation across time and place and recommendation for benchmarking. BJU Int. 2012;109:1666–73. Mashni J, Godoy G, Haarer C, Dalbagni G, Reuter VE, AlAhmadie H, et al. Prospective evaluation of plasma kinetic bipolar resection of bladder cancer: comparison to monopolar resection and pathologic findings. Int Urol Nephrol. 2014;46:1699–705. da Silva RD, Bidikov L, Michaels W, Gustafson D, Molina WR, Kim FJ. Bipolar energy in the treatment of benign prostatic hyperplasia: a current systematic review of the literature. Can J Urol. 2015;22:30–44. Stucki P, Marini L, Mattei A, Xafis K, Boldini M, Danuser H. Bipolar versus monopolar transurethral resection of the prostate: a prospective randomized trial focusing on bleeding complications. J Urol. 2015;193:1371–5. Skolarikos A, Rassweiler J, de la Rosette JJ, Alivizatos G, Scoffone C, Scarpa RM, et al. Safety and efficacy of bipolar versus monopolar transurethral resection of the prostate in patients with large prostates or severe lower urinary tract symptoms: post hoc analysis of a European multicenter randomized controlled trial. J Urol. 2015. doi:10.1016/j.juro.2015.08.083. Omar MI, Lam TB, Alexander CE, Graham J, Mamoulakis C, Imamura M, et al. Systematic review and meta-analysis of the clinical effectiveness of bipolar compared with monopolar transurethral resection of the prostate (TURP). BJU Int. 2014;113:24–35. Del Rosso A, Pace G, Masciovecchio S, Saldutto P, Galatioto GP, Vicentini C. Plasmakinetic bipolar versus monopolar transurethral resection of non-muscle invasive bladder cancer: a single center
Page 5 of 6 21 randomized controlled trial. Int J Urol. 2013;20:399–403. Prospective randomized trials comparing monopolar to bipolar bladder tumor resection. 11. Gupta NP, Saini AK, Dogra PN, Seth A, Kumar R. Bipolar energy for transurethral resection of bladder tumours at low-power settings: initial experience. BJU Int. 2011;108:553–6. 12. Geavlete B, Multescu R, Georgescu D, Jecu M, Dragutescu M, Geavlete P. Innovative technique in nonmuscle invasive bladder cancer-bipolar plasma vaporization. Urology. 2011;77:849–54. 13. Pu XY, Wang HP, Wu YL, Wang XH. Use of bipolar energy for transurethral resection of superficial bladder tumors: long-term results. J Endourol. 2008;22:545–9. 14. Beer E. Landmark article May 28, 1910: removal of neoplasms of the urinary bladder. By Edwin Beer. JAMA: J Am Med Assoc. 1983;250:1324–5. 15. Kriegmair M, Pensel J, Hofstetter AG, Fastenmeier K, Rothenberger KH, Keiditsch E, et al. Regulation high frequency diathermy for bipolar electrocoagulation? A new method for the treatment of carcinoma of the bladder. Urol Res. 1987;15:251–3. 16. Rothenberger K, Pensel J, Hofstetter A, Fastenmeier K, Keiditsch E. Controlled bipolar high-frequency coagulation for transurethral application: a new method for the destruction of urinary bladder tumors. Urol Int. 1983;38:257–62. 17. Tucker RD, Kramolowsky EV, Platz CE. In vivo effect of 5 French bipolar and monopolar electrosurgical probes on the porcine bladder. Urol Res. 1990;18:291–4. 18. Wang DS, Bird VG, Leonard VY, Plumb SJ, Konety B, Williams RD, et al. Use of bipolar energy for transurethral resection of bladder tumors: pathologic considerations. J Endourol. 2004;18:578– 82. 19. Brunken C, Qiu H, Tauber R. Transurethral resection of bladder tumours in sodium chloride solution. Urologe A. 2004;43:1101–5. 20. Lee D, Sharp VJ, Konety BR. Use of bipolar power source for transurethral resection of bladder tumor in patient with implanted pacemaker. Urology. 2005;66:194. 21. Badraoui M, Bruyere F, Lanson Y. Bipolar loop resection of a bladder tumour in a pregnant woman. Prog Urol. 2004;14:1194–5. 22. Puppo P, Bertolotto F, Introini C, Germinale F, Timossi L, Naselli A. Bipolar transurethral resection in saline (TURis ®): outcome and complication rates after the first 1000 cases. J Endourol. 2009;23: 1145–9. 23. Lagerveld BW, Koot RAC, Smits GAHJ. Thermal artifacts in bladder tumors following loop endoresection: electrovaporization v electrocauterization. J Endourol. 2004;18:583–6. 24.• Mansour AM, Shokeir AA, Tharwat M, Ali-El-Dein B, Osman Y. Pd17-10 monopolar versus bipolar transurethral resection of nonmuscle invasive bladder cancer: a single center randomized controlled trial. J Urol. 2015;193:e384–e5. Prospective randomized trials comparing monopolar to bipolar bladder tumor resection. 25. Sugihara T, Yasunaga H, Horiguchi H, Matsui H, Nishimatsu H, Nakagawa T, et al. Comparison of perioperative outcomes including severe bladder injury between monopolar and bipolar transurethral resection of bladder tumors: a population based comparison. J Urol. 2014;192:1355–9. 26.•• Venkatramani V, Panda A, Manojkumar R, Kekre NS. Monopolar versus bipolar transurethral resection of bladder tumors: a single center, parallel arm, randomized, controlled trial. J Urol. 2014;191:1703–7. Prospective randomized trials comparing monopolar to bipolar bladder tumor resection. 27. Xishuang S, Deyong Y, Xiangyu C, Tao J, Quanlin L, Hongwei G, et al. Comparing the safety and efficiency of conventional monopolar, plasmakinetic, and holmium laser transurethral resection of primary non-muscle invasive bladder cancer. J Endourol. 2010;24:69–73.
21 28.
29.
30.
31.
32.
33. 34.
35. 36.
37.
38.
39.
Curr Urol Rep (2016) 17:21
Page 6 of 6 Yang SJ, Song PH, Kim HT. Comparison of deep biopsy tissue damage from transurethral resection of bladder tumors between bipolar and monopolar devices. Korean J Urol. 2011;52:379–83. Abascal Junquera JM, Cecchini Rosell L, Salvador Lacambra C, Martos Calvo R, Celma Domenech A, Morote Robles J. Resección transuretral de próstata bipolar vs monopolar: análisis peroperatorio de los resultados. Actas Urol Esp. 2006;30:661–6. Mamoulakis C, Skolarikos A, Schulze M, Scoffone CM, Rassweiler JJ, Alivizatos G, et al. Results from an international multicentre double-blind randomized controlled trial on the perioperative efficacy and safety of bipolar vs monopolar transurethral resection of the prostate. BJU Int. 2011;109:240–8. Mamoulakis C, Ubbink DT, de la Rosette JJMCH. Bipolar versus monopolar transurethral resection of the prostate: a systematic review and meta-analysis of randomized controlled trials. Eur Urol. 2009;56:798–809. Qu L, Wang X, Huang X, Zhang Y, Zeng X. Use of a novel ex-vivo model to compare the hemostatic properties of plasmakinetic resection, transurethral vaporization resection and conventional transurethral resection of the prostate. Urology. 2007;70:1034–8. Hahn RG. Transurethral resection syndrome after transurethral resection of bladder tumours. Can J Anaesth. 1995;42:69–72. Dorotta I, Basali A, Ritchey M, O’Hara Jr JF, Sprung J. Transurethral resection syndrome after bladder perforation. Anesth Analg. 2003;97:1536–8. Ho HSS, Cheng CWS. Bipolar transurethral resection of prostate: a new reference standard? Curr Opin Urol. 2008;18:50–5. Reich O. Editorial comment on: a prospective randomized study comparing monopolar and bipolar transurethral resection of prostate using transurethral resection in saline (TURIS) system. Eur Urol. 2007;52:523–4. Richards KA, Smith ND, Steinberg GD. The importance of transurethral resection of bladder tumor in the management of nonmuscle invasive bladder cancer: a systematic review of novel technologies. J Urol. 2014;191:1655–64. Lee SH, Jeong CW, Lee HJ, Yoon MH, Kim WM. Ultrasound guided obturator nerve block: a single interfascial injection technique. J Anesth. 2011;25:923–6. Khorrami M, Hadi M, Javid A, Izadpahani MH, Mohammadi Sichani M, Zargham M, et al. A comparison between blind and nerve stimulation guided obturator nerve block in transurethral resection of bladder tumor. J Endourol. 2012;26:1319–22.
40.
Kihl B, Nilson AE, Pettersson S. Thigh adductor contraction during transurethral resection of bladder tumours: evaluation of inactive electrode placement and obturator nerve topography. Scand J Urol Nephrol. 1981;15:121–5. 41. McKiernan JM, Kaplan SA, Santarosa RP, Te AE, Sawczuk IS. Transurethral electrovaporization of bladder cancer. Urology. 1996;48:207–10. 42. Chakravarti A, Day DW, MacDermott S. Extravesical transitional cell carcinoma as a result of implantation after perforation of the bladder. BJU Int. 2000;85:1150–1. 43. Skolarikos A, Chrisofos M, Ferakis N, Papatsoris A, Dellis A, Deliveliotis C. Does the management of bladder perforation during transurethral resection of superficial bladder tumors predispose to extravesical tumor recurrence? J Urol. 2005;173:1908–11. 44. Traxer O, Pasqui F, Gattegno B, Pearle MS. Technique and complications of transurethral surgery for bladder tumours. BJU Int. 2004;94:492–6. 45. Balbay MD, Cimentepe E, Unsal A, Bayrak O, Koc A, Akbulut Z. The actual incidence of bladder perforation following transurethral bladder surgery. J Urol. 2005;174:2260–2. 46. Geavlete B, Multescu R, Georgescu D, Stanescu F, Jecu M, Geavlete P. Narrow band imaging cystoscopy and bipolar plasma vaporization for large nonmuscle-invasive bladder tumors—results of a prospective, randomized comparison to the standard approach. Urology. 2012;79:846–52. 47. Geavlete B, Stanescu F, Moldoveanu C, Geavlete P. Continuous vs conventional bipolar plasma vaporisation of the prostate and standard monopolar resection: a prospective, randomised comparison of a new technological advance. BJU Int. 2014;113:288–95. 48. Stanescu F, Geavlete B, Jecu M, Moldoveanu C, Ene C, Bulai C, et al. C129: diagnostic and safety advantages of a combined NBI– plasma vaporization approach in large non-muscle invasive bladder tumors. Eur Urol Suppl. 2014;13, e1314. 49. Geavlete B, Stanescu F, Moldoveanu C, Jecu M, Adou L, Bulai C, et al. NBI cystoscopy and bipolar electrosurgery in NMIBC management—an overview of daily practice. J Med Life. 2013;6:140–5. 50. Canter DJ, Ogan K, Master VA. Initial North American experience with the use of the Olympus Button Electrode for vaporization of bladder tumors. Can J Urol. 2012;19:6211–6.
UROTHELIAL CANCER (A SAGALOWSKY, SECTION EDITOR)
A Review Comparing Experience and Results with Bipolar Versus Monopolar Resection for Treatment of Bladder Tumors Yasser Osman 1 & Ahmed M. Harraz 1
# Springer Science+Business Media New York 2016
Abstract The standard treatment of non-muscle invasive bladder cancer (NMIBC) is transurethral resection (TUR) commonly using a monopolar electrocautery system. This system requires high energy and voltage to allow an electric current to run from the loop to the patient’s skin. The heat generated leads to desiccation of small cells and difficulty to perform adequate histological analysis for severely cauterized pieces of tissues. On contrary, the electric current in bipolar systems does not traverse the patient and hence lower energy and voltage are used and minimal tissue damage is anticipated. In addition, the use of saline as an irrigant fluid eliminates the potential TUR syndrome from excess hypotonic fluid reabsorption. Furthermore, the lower energy dissipates as heat in tissues contributing to adequate hemostasis. This review presents the most recent studies and evidence on the differences between monopolar and bipolar systems for TUR of NMIBC as regards the perioperative and long-term outcomes. Keywords Non-muscle invasive bladder cancer . Bipolar plasma kinetic energy . Transurethral resection
Introduction Urothelial (UC) carcinoma of the bladder is the most common malignancy of the urinary tract and it ranks the 7th and 17th This article is part of the Topical Collection on Urothelial Cancer * Yasser Osman [email protected]
1
Urology and Nephrology Center, Mansoura University, 70th Gomhoria St., 35516 Mansoura, Egypt
most common cancer worldwide among males and females, respectively [1]. Each year, approximately 110,500 men and 70,000 women are newly diagnosed with approximately 75 % of patients present with non-muscle invasive bladder cancer (NMIBC) [1, 2]. The most significant risk factor is smoking accounting for more than half of the patients while genetic and epigenetic alterations related to carcinogenesis in the bladder have been linked to environmental and occupational factors in non-smokers [3]. The mortality from UC reaches up to 38,200 patients in the European Union and 17,000 in US patients [1]. The standard treatment for NMIBC is transurethral resection (TUR) aiming at confirming the diagnosis and removal of all visible lesions which is crucial for prognosis [4]. Monopolar systems used for TUR of NMIBC require the use of high energy and voltage to allow the current transmission from the loop to the skin. The heat generated from this current not only facilitates the cutting of tissues; unfortunately, it causes desiccation of small cells. In addition, it is difficult to perform adequate histological analysis for severely cauterized pieces of tissues [5]. Bipolar technology has been introduced and is gaining popularity among urologists for treatment of benign prostatic obstruction [6]. In this system, the electric current completes the circuit, without passing through the patient, between the two poles situated on the tip (Btrue^) or between the active (resection loop) and passive pole situated on specifically developed sheath (Bquasi-^). This allows isotonic fluid to be used for irrigation instead of electrolyte-free solutions and, hence, eliminating the occurrence of transurethral syndrome with monopolar systems. In addition, the bipolar systems use the plasma formed at the surface of the electrode to minimize voltage needed for tissue resection. Furthermore, the energy and voltage required is lower as there is a short distance to travel compared to loop-to-skin distance in monopolar system [6]. Another difference between the monopolar and bipolar
21
Curr Urol Rep (2016) 17:21
Page 2 of 6
systems is the coagulation mechanism. In the bipolar system, the voltage is kept low and the energy dissipates as heat in tissues leading to the formation of coagulum and hemostasis. Recently, comparable outcomes between bipolar and monopolar TURP were reported as regards perioperative morbidity and improvement in symptom scores even in subpopulations with large prostates [6–9]. In this context, the use of bipolar technology for TUR of bladder tumor (TURBT) is growing and has become of great interest in many centers [5, 10••, 11–13]. This review presents the current status of bipolar TURBT compared with traditional monopolar TURBT.
Evolution of Bipolar TURBT Traditionally, TURBT was performed with monopolar electrocautery as the base of diagnosis and initial therapy since its introduction in 1910 [14]. Three decades ago, the concept of controlled bipolar high-frequency coagulation for transurethral destruction of urinary bladder tumors was experimentally introduced [15, 16]. Few years later, in vivo trials showed that bipolar probes could electrodesiccate at a lower power and with less tissue damage in a porcine bladder model [17]. Nevertheless, the clinical application was delayed in order to ensure that bipolar probes could provide meticulous, safe, and complete tumor resection. Moreover, excessive tissue destruction should be avoided to allow adequate pathological assessment. A decade ago, two small case series were reported from USA and Germany and showed bipolar tumor resection can be performed safely with excellent control of the extent of cutting and the lack of nerve stimulation. Bladder tissue obtained from bipolar TURBT is of the same histologic quality as that obtained from conventional monopolar TURBT and provides the urologists with reliable and complete diagnosis [18, 19]. At that time, the technique was generally limited for risky patients as pregnant women and those with implanted pacemakers [20, 21]. Pu et al. reported the first wide clinical experience in year 2008 where 121 patients were treated with bipolar resection of superficial bladder tumors. Adductor contractions were observed in 4.9 % of the patients with bladder wall perforation in 1.7 % while hematuria was encountered in 2.5 %. The procedure was described to be a safe and effective modality in treating superficial bladder tumors [13]. In an Italian report, Puppo et al. reported 1000 cases with transurethral resection in saline utilizing the bipolar devices including 480 cases of bladder neoplasm resection. Obturator nerve stimulation was reported in 2 % of cases with no bladder wall perforation. Clot retention was experienced in 2 % of patients with less than 1 % requiring blood transfusion. The technique was described to guarantee maximum safety for the patients [22].
Evaluation of Bipolar TURBT Yet, comparative studies were mandatory to critically judge the outcome compared with the standard monopolar resection. Nine comparative studies were reviewed [5, 10••, 18, 23, 24•, 25, 26••, 27, 28] among three were controlled prospective randomized trials [10••, 24•, 26••]. Anesthesia Time The loop size utilized with bipolar resection is generally smaller than the classic monopolar loop typically used [28]. On the other hand, utilizing bipolar resection was expected to reduce resection time due to reduced adhesions of residual fragments to the loop of a resectoscope which are easily removed by acting on the cutting function with the loop in the bladder lumen. In contrast, the monopolar device requires a manual and mechanical removal of the residual chips through extraction of the instrument from its sheath which prolongs the procedure [29]. Generally, non-randomized [5, 25, 27, 28] as well as randomized [10••, 24•, 26••] studies confirmed that resection time was equal regardless of the type of energy utilized. Bleeding Based on the prostatic experience, bipolar resection was believed to induce better hemostasis as the deep coagulation and the cut and seal property of the bipolar current contribute to augment the ability to control bleeding points [30–32]. Apart from a single non-randomized comparative study that showed a significant drop of hemoglobin level with monopolar TURBT compared with bipolar resection that was not reflected on the transfusion rate [28], bleeding events, transfusion rates, need for re-coagulation, and decrease in packed cell volume were persistently reported to be comparable between both techniques in both non-randomized as well as randomized reports [5, 10••, 24•, 25, 26••, 27, 28]. Transurethral Resection Syndrome Transurethral resection syndrome (TUR) syndrome after bladder tumor resection was first described by Hahn in 1995 [33]. The use of normal saline for bladder irrigation during bipolar resection practically precludes the possibility of TUR syndrome. Generally, TUR syndrome after monopolar TURBT is rarely reported with an incidence around 2 % [34]. The rarity of this complication led to absence of a significant difference between both techniques in clinical TUR syndrome or even subclinical change in sodium level between monopolar and bipolar tumor resection [10••, 26••, 27].
Curr Urol Rep (2016) 17:21
Urethral Stricture Ho reported higher incidence of urethral strictures in patients treated with bipolar resection of the prostate compared with monopolar resection although it does not reach a statistical significance [35]. It was suggested that increased electrical density on the outer surface of the sheath of the resectoscope with minute damage on its surface can cause dispersions of flow on the urethral mucosa. Moreover, the use of conductive lubricants might increase the insult [36]. In early reports of bipolar TURBT, high incidence of urethral stricture (4 %) was reported [13]. Later, Puppo et al. reported lower incidence and advised a new loop for each resection to decrease such sequel [22]. Both non-randomized and randomized trials denied a significant difference between either technique in the development of urethral stricture [10••, 27]. Obturator Jerk An incidence of obturator jerk during transurethral resection of bladder tumors is variable according to the type of anesthesia employed and the site of the tumor. Typically, general anesthesia with neuromuscular paralysis is advised to decrease the likelihood of obturator reflex during TURBT for laterally situated tumors [37]. Lee et al. described a technique of ultrasound-guided obturator nerve block in which 1 % lidocaine with epinephrine is injected in the fascial space between adductor longus and adductor brevis muscles with 96 % success rate under spinal anesthesia [38]. A technique of transurethral obturator nerve block was also described with similar success rate [39]. In monopolar resection, the distance between the resecting loop and the return electrode (skin pad) is long resulting in the generation of a high voltage to push the current to the return electrode, explaining the high incidence of obturator nerve stimulation especially with the close proximity between the lateral wall of the bladder and the obturator nerve. A possible mechanism for obturator reflex with bipolar resection includes current transmission secondary to the initial high voltage needed to generate the plasma vapor pocket. Current mushrooming occurs around the electrode and is transmitted a few millimeters deep in the body. The close proximity of the bladder wall and the nerve means that even that limited transmission is sufficient to induce nerve stimulation [11, 22]. The classic incidence of obturator jerk with monopolar resection is 11 % [40, 41] while it ranges in bipolar series from 2 to 4.9 % [13, 22]. Reporting the incidence and the differences between both techniques in inducing obturator reflex is the seat of strong debate and confusion. Some reports described obturator reflex to occur in nearly half the patients [26••] and others reported an incidence around 1 % [10••] regardless of the type of power utilized. One nonrandomized report favored the bipolar TURBT in abolishing
Page 3 of 6 21
the obturator reflex in a statistically significant way compared with monopolar TURBT [27]. A similar study showed equal incidence between both techniques with an equal need of muscle relaxants [5]. The debate extends further into the randomized trials where two studies denied a significant difference between both techniques [10••, 26••] with the third study showing a significant decrease of the incidence of nerve stimulation from 26 % with monopolar resection compared to 4.8 % in the bipolar setting [24•].
Bladder Perforation Although the incidence of bladder injury is rare but it is of concern as it has a high risk of extravesical tumor seeding [8, 42, 43]. Real incidence of bladder perforation might be underestimated possibly because of underreporting, and it ranges from 1.7 to 5 % [13, 44]. Under dedicated postoperative imaging, real incidence of perforation might reach up to 58 % [45]. Similar to obturator reflex debate, the value of bipolar resection in decreasing the incidence of bladder perforation is yet to be confirmed. In a population-based Japanese study that included around 30,000 patients from 788 hospital records, incidence of severe bladder injury was significantly higher in monopolar TURBT based on multivariate analysis [25]. Other non-randomized trials provided opposing conclusions [5, 27]. Mansor et al., in a controlled randomized trial, reported 13.2 % perforation rate with monopolar resection that was significantly higher than the 2.4 % incidence reported with the bipolar resection [24•]. Interestingly, the other two controlled randomized trials failed to sustain that conclusion [10••, 26••]. In another study, Gupta reported a significant rate of obturator jerks and subsequent perforation in their first 10 patients when the power setting of the bipolar machine was adjusted for 160 and 80 W for cutting and coagulation, respectively [11]. They showed that such complications had been eliminated by using a lower power setting of 50 and 40 W [11]. This report should be taken cautiously as the high power setting (or even higher) was adopted in other experiences, and such observation was not reported [5, 13, 22, 27, 28]. To put an end to the controversy regarding the real impact of bipolar TURBT in reducing incidence of obturator nerve stimulation and bladder perforation, we do believe that urologic literature is lacking a critically judged randomized trial. Therefore, a multicenter trial is warranted with standardization of the type of the anesthesia, site of the tumor, skill of the surgeon as well as the power level for both cutting and coagulation mood. Moreover, precise definitions of obturator reflex and bladder perforation are to be provided possibly with EMG recording and routine post-operative imaging.
21
Curr Urol Rep (2016) 17:21
Page 4 of 6
Catheterization, Hospital Stay, and Cost The impact of bipolar resection on catheterization time was controversial on non-randomized trials [5, 28]. Del Rosso in a randomized clinical trial showed significant reduction of the catheterization time with bipolar TURBT into 1.3 days compared with 2.3 days in the monopolar arm [10••]. The policy of hospital stay is variable from institute to another and from a country to another. There is a universal agreement that application of bipolar resection would decrease the hospital stay [10••, 25, 27] possibly because of shorter irrigation [27] and catheterization [10] time. In a population-based study, the overall cost was significantly higher in the monopolar arm compared to bipolar in both univariate and multivariate analyses probably because of shorter hospital stay [25]. Pathological Quality Rationally, the pathological specimen retrieved should not be compromised and must be suitable for elegant pathological assessment. Two non-randomized trials showed that muscularis propria was present in 100 % of cases with bipolar resection compared with 90 to 100 % in monopolar resection [5, 18]. Similarly, Venkatramani et al. confirmed that the deep muscle was retrieved in around 95 % of cases of both groups with no difference based on a controlled randomized trial [26••]. On the other hand, others showed that deep biopsy specimen thickness was significantly thinner with bipolar resection compared with the monopolar resection (2.3 ± 0.9 vs. 3 ± 1.4 mm). Nevertheless, this was sufficient for the pathologist to make appropriate diagnosis in all the cases [28]. In monopolar resection, electrical injury is directed into the tissues and the electrical resistance creates temperature as high as 400 ° C with tissue desiccation and considerable collateral tissue damage. On the other hand, the radiofrequency energy of the bipolar systems converts the conductive medium into a plasma field of highly ionized particles which disrupts the organic bonds between the tissues which allows the thermal effect to occur at a much lower temperature (40 to 70 °C) (37– 39). Thermal damage was categorized into three groups according to quantity of thermal artifacts. Grade 1 was defined as cautery artifact less than one third of the entire specimen. Tissue hips with one third to two thirds cautery artifacts were categorized as grade 2, and tissue chips with over two thirds cautery artifacts were categorized as grade 3 [28]. Several non-controlled studies showed that the incidence of cautery artifact was comparable in the specimens retrieved from both techniques and does not interfere with the diagnostic readability of the specimen [5, 18, 23, 28]. Lagerveld et al. [23] measured the mean depth of the thermal artifact zone was 0.237 mm in the bipolar arm compared with 0.260 mm in the monopolar group. This difference is not significant (P = 0.8). Based on two controlled randomized trials, while the
pathologist was blinded to the technique utilized, the thermal artifacts were significantly higher in the monopolar resection compared with bipolar TURBT [10••, 26••]. Recurrence Rate It was apparent that there was no impact on the recurrence rate whatever type of energy utilized. Median time until bladder recurrence and overall 2-year recurrence rate were equal in both techniques even when stratified into low-, intermediate-, and high-risk groups [10••, 27].
Bipolar Plasma Vaporization This technique was first introduced by a Romanian group in 2011 [12] and starts by multiple biopsies from the exophytic part of the tumor to judge the tumor grade. This is to be followed by tumor plasma vaporization. Upon completion, multiple biopsies of the tumor bed are performed in order to judge the tumor stage. Later, they provided a randomized trial comparing this technique with classic monopolar resection with significantly improved resection time, hemostasis, catheterization time, and hospital stay. Also, they showed a reduced incidence of obturator nerve stimulation and bladder wall perforation significantly. Moreover, residual tumors at second look, primary site recurrence as well as overall recurrence rate at 1 year were significantly higher in the monopolar arm. Notably, these outstanding results were reported when this therapeutic approach is combined with narrow band imaging (NBI) in order to improve the diagnostic ability [46–49]. These data should be interpreted separately from other reports of bladder tumor management utilizing the bipolar energy as the technique includes tumor vaporization rather than resection. Concerns should be raised regarding proper pathological assessment of the tumor bed. A superficial muscle invasion might be easily overlooked during tumor ablation with negative biopsies from deeper muscle layer. This technique was not reproduced with the exception of a small Canadian study [50].
Conclusion The use of bipolar technology in transurethral resection of non-muscle invasive bladder cancer is a safe and effective modality. No solid evidence can be provided that technique would lead to improvement in resection time or hemostasis. Similarly, the current level of evidence did not reduce incidence of urethral stricture, TUR syndrome, or tumor recurrence rate. On the other hand, a better specimen could be provided for pathological assessment with significantly lower thermal artifacts. A well-designed randomized trial is
Curr Urol Rep (2016) 17:21
mandatory to critically judge the impact of bipolar resection upon obturator nerve stimulation and bladder perforation. Compliance with Ethical Standards Conflict of Interest Yasser Osman and Ahmed M Harraz each declare no potential conflicts of interest. Human and Animal Rights and Informed Consent This article does not contain any studies with human or animal subjects performed by any of the authors.
References Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance 1.
2.
3.
4.
5.
6.
7.
8.
9.
10.••
Burger M, Catto JW, Dalbagni G, Grossman HB, Herr H, Karakiewicz P, et al. Epidemiology and risk factors of urothelial bladder cancer. Eur Urol. 2013;63:234–41. Babjuk M, Burger M, Zigeuner R, Shariat SF, van Rhijn BW, Comperat E, et al. EAU guidelines on non-muscle-invasive urothelial carcinoma of the bladder: update 2013. Eur Urol. 2013;64:639–53. Kiriluk KJ, Prasad SM, Patel AR, Steinberg GD, Smith ND. Bladder cancer risk from occupational and environmental exposures. Urol Oncol. 2012;30:199–211. Mariappan P, Finney SM, Head E, Somani BK, Zachou A, Smith G, et al. Good quality white-light transurethral resection of bladder tumours (GQ-WLTURBT) with experienced surgeons performing complete resections and obtaining detrusor muscle reduces early recurrence in new non-muscle-invasive bladder cancer: validation across time and place and recommendation for benchmarking. BJU Int. 2012;109:1666–73. Mashni J, Godoy G, Haarer C, Dalbagni G, Reuter VE, AlAhmadie H, et al. Prospective evaluation of plasma kinetic bipolar resection of bladder cancer: comparison to monopolar resection and pathologic findings. Int Urol Nephrol. 2014;46:1699–705. da Silva RD, Bidikov L, Michaels W, Gustafson D, Molina WR, Kim FJ. Bipolar energy in the treatment of benign prostatic hyperplasia: a current systematic review of the literature. Can J Urol. 2015;22:30–44. Stucki P, Marini L, Mattei A, Xafis K, Boldini M, Danuser H. Bipolar versus monopolar transurethral resection of the prostate: a prospective randomized trial focusing on bleeding complications. J Urol. 2015;193:1371–5. Skolarikos A, Rassweiler J, de la Rosette JJ, Alivizatos G, Scoffone C, Scarpa RM, et al. Safety and efficacy of bipolar versus monopolar transurethral resection of the prostate in patients with large prostates or severe lower urinary tract symptoms: post hoc analysis of a European multicenter randomized controlled trial. J Urol. 2015. doi:10.1016/j.juro.2015.08.083. Omar MI, Lam TB, Alexander CE, Graham J, Mamoulakis C, Imamura M, et al. Systematic review and meta-analysis of the clinical effectiveness of bipolar compared with monopolar transurethral resection of the prostate (TURP). BJU Int. 2014;113:24–35. Del Rosso A, Pace G, Masciovecchio S, Saldutto P, Galatioto GP, Vicentini C. Plasmakinetic bipolar versus monopolar transurethral resection of non-muscle invasive bladder cancer: a single center
Page 5 of 6 21 randomized controlled trial. Int J Urol. 2013;20:399–403. Prospective randomized trials comparing monopolar to bipolar bladder tumor resection. 11. Gupta NP, Saini AK, Dogra PN, Seth A, Kumar R. Bipolar energy for transurethral resection of bladder tumours at low-power settings: initial experience. BJU Int. 2011;108:553–6. 12. Geavlete B, Multescu R, Georgescu D, Jecu M, Dragutescu M, Geavlete P. Innovative technique in nonmuscle invasive bladder cancer-bipolar plasma vaporization. Urology. 2011;77:849–54. 13. Pu XY, Wang HP, Wu YL, Wang XH. Use of bipolar energy for transurethral resection of superficial bladder tumors: long-term results. J Endourol. 2008;22:545–9. 14. Beer E. Landmark article May 28, 1910: removal of neoplasms of the urinary bladder. By Edwin Beer. JAMA: J Am Med Assoc. 1983;250:1324–5. 15. Kriegmair M, Pensel J, Hofstetter AG, Fastenmeier K, Rothenberger KH, Keiditsch E, et al. Regulation high frequency diathermy for bipolar electrocoagulation? A new method for the treatment of carcinoma of the bladder. Urol Res. 1987;15:251–3. 16. Rothenberger K, Pensel J, Hofstetter A, Fastenmeier K, Keiditsch E. Controlled bipolar high-frequency coagulation for transurethral application: a new method for the destruction of urinary bladder tumors. Urol Int. 1983;38:257–62. 17. Tucker RD, Kramolowsky EV, Platz CE. In vivo effect of 5 French bipolar and monopolar electrosurgical probes on the porcine bladder. Urol Res. 1990;18:291–4. 18. Wang DS, Bird VG, Leonard VY, Plumb SJ, Konety B, Williams RD, et al. Use of bipolar energy for transurethral resection of bladder tumors: pathologic considerations. J Endourol. 2004;18:578– 82. 19. Brunken C, Qiu H, Tauber R. Transurethral resection of bladder tumours in sodium chloride solution. Urologe A. 2004;43:1101–5. 20. Lee D, Sharp VJ, Konety BR. Use of bipolar power source for transurethral resection of bladder tumor in patient with implanted pacemaker. Urology. 2005;66:194. 21. Badraoui M, Bruyere F, Lanson Y. Bipolar loop resection of a bladder tumour in a pregnant woman. Prog Urol. 2004;14:1194–5. 22. Puppo P, Bertolotto F, Introini C, Germinale F, Timossi L, Naselli A. Bipolar transurethral resection in saline (TURis ®): outcome and complication rates after the first 1000 cases. J Endourol. 2009;23: 1145–9. 23. Lagerveld BW, Koot RAC, Smits GAHJ. Thermal artifacts in bladder tumors following loop endoresection: electrovaporization v electrocauterization. J Endourol. 2004;18:583–6. 24.• Mansour AM, Shokeir AA, Tharwat M, Ali-El-Dein B, Osman Y. Pd17-10 monopolar versus bipolar transurethral resection of nonmuscle invasive bladder cancer: a single center randomized controlled trial. J Urol. 2015;193:e384–e5. Prospective randomized trials comparing monopolar to bipolar bladder tumor resection. 25. Sugihara T, Yasunaga H, Horiguchi H, Matsui H, Nishimatsu H, Nakagawa T, et al. Comparison of perioperative outcomes including severe bladder injury between monopolar and bipolar transurethral resection of bladder tumors: a population based comparison. J Urol. 2014;192:1355–9. 26.•• Venkatramani V, Panda A, Manojkumar R, Kekre NS. Monopolar versus bipolar transurethral resection of bladder tumors: a single center, parallel arm, randomized, controlled trial. J Urol. 2014;191:1703–7. Prospective randomized trials comparing monopolar to bipolar bladder tumor resection. 27. Xishuang S, Deyong Y, Xiangyu C, Tao J, Quanlin L, Hongwei G, et al. Comparing the safety and efficiency of conventional monopolar, plasmakinetic, and holmium laser transurethral resection of primary non-muscle invasive bladder cancer. J Endourol. 2010;24:69–73.
21 28.
29.
30.
31.
32.
33. 34.
35. 36.
37.
38.
39.
Curr Urol Rep (2016) 17:21
Page 6 of 6 Yang SJ, Song PH, Kim HT. Comparison of deep biopsy tissue damage from transurethral resection of bladder tumors between bipolar and monopolar devices. Korean J Urol. 2011;52:379–83. Abascal Junquera JM, Cecchini Rosell L, Salvador Lacambra C, Martos Calvo R, Celma Domenech A, Morote Robles J. Resección transuretral de próstata bipolar vs monopolar: análisis peroperatorio de los resultados. Actas Urol Esp. 2006;30:661–6. Mamoulakis C, Skolarikos A, Schulze M, Scoffone CM, Rassweiler JJ, Alivizatos G, et al. Results from an international multicentre double-blind randomized controlled trial on the perioperative efficacy and safety of bipolar vs monopolar transurethral resection of the prostate. BJU Int. 2011;109:240–8. Mamoulakis C, Ubbink DT, de la Rosette JJMCH. Bipolar versus monopolar transurethral resection of the prostate: a systematic review and meta-analysis of randomized controlled trials. Eur Urol. 2009;56:798–809. Qu L, Wang X, Huang X, Zhang Y, Zeng X. Use of a novel ex-vivo model to compare the hemostatic properties of plasmakinetic resection, transurethral vaporization resection and conventional transurethral resection of the prostate. Urology. 2007;70:1034–8. Hahn RG. Transurethral resection syndrome after transurethral resection of bladder tumours. Can J Anaesth. 1995;42:69–72. Dorotta I, Basali A, Ritchey M, O’Hara Jr JF, Sprung J. Transurethral resection syndrome after bladder perforation. Anesth Analg. 2003;97:1536–8. Ho HSS, Cheng CWS. Bipolar transurethral resection of prostate: a new reference standard? Curr Opin Urol. 2008;18:50–5. Reich O. Editorial comment on: a prospective randomized study comparing monopolar and bipolar transurethral resection of prostate using transurethral resection in saline (TURIS) system. Eur Urol. 2007;52:523–4. Richards KA, Smith ND, Steinberg GD. The importance of transurethral resection of bladder tumor in the management of nonmuscle invasive bladder cancer: a systematic review of novel technologies. J Urol. 2014;191:1655–64. Lee SH, Jeong CW, Lee HJ, Yoon MH, Kim WM. Ultrasound guided obturator nerve block: a single interfascial injection technique. J Anesth. 2011;25:923–6. Khorrami M, Hadi M, Javid A, Izadpahani MH, Mohammadi Sichani M, Zargham M, et al. A comparison between blind and nerve stimulation guided obturator nerve block in transurethral resection of bladder tumor. J Endourol. 2012;26:1319–22.
40.
Kihl B, Nilson AE, Pettersson S. Thigh adductor contraction during transurethral resection of bladder tumours: evaluation of inactive electrode placement and obturator nerve topography. Scand J Urol Nephrol. 1981;15:121–5. 41. McKiernan JM, Kaplan SA, Santarosa RP, Te AE, Sawczuk IS. Transurethral electrovaporization of bladder cancer. Urology. 1996;48:207–10. 42. Chakravarti A, Day DW, MacDermott S. Extravesical transitional cell carcinoma as a result of implantation after perforation of the bladder. BJU Int. 2000;85:1150–1. 43. Skolarikos A, Chrisofos M, Ferakis N, Papatsoris A, Dellis A, Deliveliotis C. Does the management of bladder perforation during transurethral resection of superficial bladder tumors predispose to extravesical tumor recurrence? J Urol. 2005;173:1908–11. 44. Traxer O, Pasqui F, Gattegno B, Pearle MS. Technique and complications of transurethral surgery for bladder tumours. BJU Int. 2004;94:492–6. 45. Balbay MD, Cimentepe E, Unsal A, Bayrak O, Koc A, Akbulut Z. The actual incidence of bladder perforation following transurethral bladder surgery. J Urol. 2005;174:2260–2. 46. Geavlete B, Multescu R, Georgescu D, Stanescu F, Jecu M, Geavlete P. Narrow band imaging cystoscopy and bipolar plasma vaporization for large nonmuscle-invasive bladder tumors—results of a prospective, randomized comparison to the standard approach. Urology. 2012;79:846–52. 47. Geavlete B, Stanescu F, Moldoveanu C, Geavlete P. Continuous vs conventional bipolar plasma vaporisation of the prostate and standard monopolar resection: a prospective, randomised comparison of a new technological advance. BJU Int. 2014;113:288–95. 48. Stanescu F, Geavlete B, Jecu M, Moldoveanu C, Ene C, Bulai C, et al. C129: diagnostic and safety advantages of a combined NBI– plasma vaporization approach in large non-muscle invasive bladder tumors. Eur Urol Suppl. 2014;13, e1314. 49. Geavlete B, Stanescu F, Moldoveanu C, Jecu M, Adou L, Bulai C, et al. NBI cystoscopy and bipolar electrosurgery in NMIBC management—an overview of daily practice. J Med Life. 2013;6:140–5. 50. Canter DJ, Ogan K, Master VA. Initial North American experience with the use of the Olympus Button Electrode for vaporization of bladder tumors. Can J Urol. 2012;19:6211–6.
